Smart grid interface relay and breaker

ABSTRACT

A controllable main breaker includes a main breaker sized to fit within an existing panel slot of an electrical panel. The main breaker comprises a trigger to open the main breaker in response to a thermal fault or overcurrent event. The controllable main breaker further includes an auxiliary shell sized to fit within at least one adjacent breaker slot. The auxiliary shell includes a controllable actuator that mechanically opens the main breaker.

CROSS REFERENCE TO OTHER APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 63/293,014 entitled SMART GRID INTERFACE RELAY AND BREAKER filedDec. 22, 2021 which is incorporated herein by reference for allpurposes.

BACKGROUND OF THE INVENTION

Any backup power source, be it a generator or a solar battery, requiresa way to isolate from the grid. For solar battery systems, existingmechanisms for implementing such isolation can be labor and timeintensive to install, requiring a significant amount of electrical work.It would be beneficial to have a way to more efficiently implement gridisolation mechanisms.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention are disclosed in the followingdetailed description and the accompanying drawings.

FIG. 1 illustrates an embodiment of a power system.

FIG. 2 illustrates an embodiment of an architecture of a smart mainbreaker.

FIG. 3 illustrates an example of a location for installation of a smartmain breaker.

FIG. 4 illustrates an example of a location for installation of a smartmain breaker.

DETAILED DESCRIPTION

The invention can be implemented in numerous ways, including as aprocess; an apparatus; a system; a composition of matter; a computerprogram product embodied on a computer readable storage medium; and/or aprocessor, such as a processor configured to execute instructions storedon and/or provided by a memory coupled to the processor. In thisspecification, these implementations, or any other form that theinvention may take, may be referred to as techniques. In general, theorder of the steps of disclosed processes may be altered within thescope of the invention. Unless stated otherwise, a component such as aprocessor or a memory described as being configured to perform a taskmay be implemented as a general component that is temporarily configuredto perform the task at a given time or a specific component that ismanufactured to perform the task. As used herein, the term ‘processor’refers to one or more devices, circuits, and/or processing coresconfigured to process data, such as computer program instructions.

A detailed description of one or more embodiments of the invention isprovided below along with accompanying figures that illustrate theprinciples of the invention. The invention is described in connectionwith such embodiments, but the invention is not limited to anyembodiment. The scope of the invention is limited only by the claims andthe invention encompasses numerous alternatives, modifications andequivalents. Numerous specific details are set forth in the followingdescription in order to provide a thorough understanding of theinvention. These details are provided for the purpose of example and theinvention may be practiced according to the claims without some or allof these specific details. For the purpose of clarity, technicalmaterial that is known in the technical fields related to the inventionhas not been described in detail so that the invention is notunnecessarily obscured.

FIG. 1 illustrates an embodiment of a power system. In this example, themain panel (102) distributes electricity from a main feed (e.g., fromthe meter 104) to all of the different circuits of a location such as ahome. In this example, grid power comes from the meter. The main panelmay include a main circuit breaker 106 (also referred to herein as a“main breaker”) that disconnects the utility feed from the loads in thehouse in the event of a thermal fault, high current due to shortcircuit, etc.

In this example, the power system includes an energy storage system(ESS) 108. As one example, the energy storage system is a batterystorage that is part of an on-site solar-battery power system. In thisexample, the ESS connects through one of the branch circuits of the mainpanel in the house. For example, suppose there are 24 circuits in thehouse, where one goes to a dryer, one goes to a hot water heater, onegoes to the living room, one goes to an upstairs bedroom, etc. In thisexample, one of the circuits goes to the ESS. As one example, the ESS isa part of an onsite power system, such as an onsite solar batterysystem, that includes a photovoltaic (PV) array that generates solarpower, as well as an onsite battery storage system that is coupled tothe PV array. In some embodiments, the onsite power system includes aninverter. The inverter converts DC power from the PV array and/orbatteries to AC power that can be used to power the loads of the home,such as in conjunction with the grid, or when the home is isolated fromthe grid (e.g., due to a utility grid blackout).

In this example, the ESS, loads, meter, etc. are electrically connectedvia the bus of the main panel. Thus, if the grid is disconnected byopening the main breaker, then if the ESS is able to providevoltage/power through its connection to the bus, then the ESS canprovide power to the entire home, instead of the grid (i.e., forming amicrogrid in which the home site is isolated from the utility grid).

In existing power systems, when the utility grid goes down, the voltageon the grid drops to zero, causing the house to black out, as the home'svoltage is also brought to zero. In order to bring the home back, thehome should be disconnected from the failed grid so that the ESS can nowsupply power to the home. In some cases, this is a certificationrequirement for backup power sources to be isolated from the grid whensupplying backup power.

It would be beneficial if, in the event of a grid failure, or in theevent of a predicted or anticipated grid failure, or it is detected thatthe health of the grid is declining, that the home could be quicklydisconnected from the grid to allow for operating in a backup power mode(e.g., where the ESS is the power source). In some embodiments, if thisdisconnect occurs sufficiently quickly (e.g., several 60 Hz cycles),then the operation of digital electronics within the home will not beinterrupted. This would also be beneficial in the absence of gridfailures, for example when there may be financial benefits to isolatingfrom the grid.

One example of implementing a grid disconnect is to include acontrollable relay in series with the main breaker. For example, a relayis inserted between the meter and the panel. The entire home may then bedisconnected from the grid by opening the relay, allowing the whole hometo be powered from the connected ESS.

In some cases, the meter is in the main panel, and the two are unable tobe separated. In some embodiments, to address this, another panel isinstalled, where existing circuit breakers are moved from their originalpanel to the new panel. The new panel is then fed from the old panel,where a relay such as that described above is installed between the twopanels. As one example, the new panel (also referred to herein as a“grid interface panel”) includes an integrated relay. In this case,while the loads are still moved from an existing panel to a new one atthe time of installation, a separate relay need not be installed betweenthe old panel and in the new panel (as it is integrated in the newpanel).

There are various challenges with the installation of the new panelboxes described above. One example is the long installation timerequired to install such boxes. Another issue is load relocation. Forexample, one installation scenario involves relocating circuits that arein a home's existing main panel, for example by installing a bridge boxas a sub-panel, and then rewiring all of the circuits from the existingmain panel to the sub-panel. Even installation scenarios that do notinvolve load relocation can be time consuming. For example, at aminimum, multiple large gauge conductors would still need to be routedinto and out of the newly installed box, which is time-consuming andexpensive.

An alternative embodiment for providing a controllable grid interfacemechanism is to replace an existing main breaker with what is referredto herein as an intelligent, or smart, main breaker, where the smartmain breaker described herein provides not only the safety functionalityof main breakers, but also provides controllable actuation of the mainbreaker, so that it can effectively operate as a controllable gridinterconnect switch as well (e.g., to isolate from, or reconnect to thegrid as desired). Further embodiments of a smart main breaker aredescribed below.

Described herein are embodiments of a smart main breaker that, inaddition to performing the function of a breaker for safety, alsoprovides the function of a microgrid interconnect device. Further, theintegrated smart main breaker is packaged in a form factor that isdesigned to be plugged into the same location as a home's existing mainbreaker.

As will be described herein, the integrated device provides multiplefunctions in a single package. For example, the integrated deviceincludes breaker functionality to serve the function of overcurrent andthermal safety protection—that is, it provides a safety mechanism forinterrupting current in an overcurrent situation. The integrated deviceis also controllable, allowing actuation of the breaker to disconnectthe home site from the grid in scenarios such as brownouts or blackouts.

As will also be described in further detail below, the integrated smartmain breaker device is programmed so that it can autonomously makedecisions on when to close or open the main breaker to connect ordisconnect the home from the grid. The intelligent main breaker alsoincludes communications to allow coordination with a power source device(e.g., inverter of a home solar battery system).

As will be described in further detail below, the form factor of thecontrollable main breaker device is selected so that it can be packagedinto existing panels, avoiding the need (and associated time andexpense) to install a new panel and perform relocating of loads.

Embodiments of the smart main breaker device described herein addressthe aforementioned issues with existing implementations of microgridinterconnect devices. For example, using the smart grid interconnectbreaker described herein eliminates the need for installing a new box.Instead, an existing box/panel is utilized. This provides variousbenefits. For example, installation time is reduced, where thisreduction in overhead would allow an electrician to perform moreinstallations in a day.

For example, in some embodiments, an existing main breaker is replacedwith the controllable main breaker described herein that not only servesthe safety purpose of a breaker, but is also controllable so that thecircuit can be opened when desired (and not just when there is a fault).The controllable grid interface breaker mechanisms described hereinprovide various benefits, including simplified installation, as well assimplified manufacturing and certification.

Further, combining the microgrid interconnect functionality within amain breaker avoids placing the grid interconnect device in othercomponents such as meters, which would involve certification withutilities. As another example benefit, the use of such an intelligentmain breaker does not require coordination with a utility.

The following are embodiments of an intelligent main breaker that alsoprovides integrated microgrid interconnect functionality. As will bedescribed in further detail below, the intelligent main breaker providessafety functionality (via the main breaker and overcurrent and thermaltriggers), as well as microgrid interconnect functionality (e.g., byintelligent and controllable triggering of the opening and closing ofthe main breaker).

In the following examples, existing main breakers are replaced with acontrollable main breaker, or are augmented or otherwise adapted tobecome controllable to also function as a controllable grid interfacerelay. In some embodiments, existing breaker functionality is leveragedto connect or disconnect from the meter. The mechanisms described hereinprovide existing breaker safety functionality, while adding (remote)controllability of the breaker mechanism to allow smartconnect/disconnect from the grid. For example, the controllable breakersdescribed herein may be opened very quickly, as well as be closed, whilestill serving the purpose of a breaker to provide critical safetyfunctions. In some embodiments, the controllable breakers describedherein, in addition to providing safety functionality, are alsoactuatable to function as a controllable relay. Thus, in variousembodiments, the controllable grid interface breakers described hereinmay be used as a home disconnect relay (e.g., for backup purposes).

Smart Main Breaker Architecture

FIG. 2 illustrates an embodiment of an architecture of a smart mainbreaker.

As shown in this example, the intelligent main breaker 200 includes amain breaker 202. The main breaker is configured to perform the safetyfeature of providing thermal or overcurrent protection. The breakerprovides a way to disconnect the home from the grid in case of safetyissues. For example, when the main breaker is opened, the load sideconnection 204 (e.g., to home loads) and grid side connection 206 (e.g.,to the meter/grid) are electrically disconnected from each other. Whenit is safe again, a user can reset the main breaker, and reconnect thehome to the grid. In effect, main breakers provide a way where the homecan be disconnected and reconnected to the grid.

In some embodiments, the smart main breaker leverages the main breakermechanism to perform the function of a controllable interconnect switchby providing a controllable actuator that can open and close the breakeras desired (rather than only due to unsafe conditions), where thecontrollable actuator is controlled via intelligence local to the smartmain breaker, and can disconnect or reconnect the grid side from theload side (e.g., home). That is, the resettable main breaker isleveraged to also provide intelligent grid interconnect functionality,where a controllable actuator is included in the smart main breaker sothat the main breaker can also be used as a grid interconnect switch.

The following are further embodiments of an architecture of a smart mainbreaker.

Main Breaker/Safety Functionality Triggers

In some embodiments, to provide existing safety functionality, the smartmain breaker architecture includes components such as contacts that maybe opened and closed (e.g., to break or close a circuit). In someembodiments, the smart main breaker includes a spring-loaded mechanismthat snaps the contacts open when triggered. The opening of the contactsmay be triggered in a variety of ways. For example, for thermal safetypurposes, the smart main breaker includes a bimetal strip 208 that warpswhen heated, causing the trigger mechanism to be actuated when thecurrent is too high for too long (e.g., thermal tripping). In thisexample, the smart main breaker may also include, for overcurrent safetyprotection, a coil/solenoid mechanism 210, where the current flowingthrough the coil provides a linear magnetic force on an actuator. Whenthere is a high current through the breaker, the magnetic forceincreases and triggers the actuator, causing the contacts to quicklyopen. The smart main breaker may also include arc extinguishingmechanisms (e.g., arc shoots or channels such as metal fins).

Controllable Actuators for Opening and Closing the Main Breaker

In some embodiments, to provide remote control functionality, the smartmain breaker includes controllable mechanisms/actuators 212 for openingand closing the main breaker. For example, for opening the main breaker,the smart main breaker includes an additional actuator/trigger that iselectronically controllable for tripping the breaker on demand. As oneexample, the additional actuator is a coil/solenoid mechanism that iselectronically controllable (rather than, for example, being driven bythe primary breaker current). In some embodiments, the solenoid takespower from the voltage on the lines, and when disconnection from thegrid is desired, voltage is placed on the coil, which, for example,pushes another coil that pushes the trigger, causing the breaker to openwhenever desired. As shown in this example, in addition to two triggermechanisms for safety, such as the warping bimetal strip for thermaltriggering, and a solenoid/coil for high current triggering, thecontrollable breaker described herein includes an additional triggermechanism for controlling opening of the main grid interface breaker (toeffectively disconnect from the grid). In some embodiments, theadditional controllable trigger actuates in response to a command from amicrocontroller of the smart main breaker, further details of which aredescribed below.

Reset Motor

In some embodiments, in order to close the main breaker (e.g., toreconnect the load side and the grid side together), the smart mainbreaker includes a controllable mechanism such as a controllable motorfor closing or resetting the breaker when desired. Electronics forcontrolling the actuator and the reset mechanism may also be included inthe main breaker. For example, a closing motor may be included that, oncommand, reloads springs for closing the contacts of the controllablebreaker. This provides, for example, a controllable spring-loadedtriggerable contact that may be opened and closed when desired. In someembodiments, the controllable reset mechanism is controlled by commandsfrom a microcontroller of the smart main breaker, further details ofwhich are described below.

Interlocking Mechanism

In some embodiments the controllable breaker is configured with logicthat detects when the breaker is triggered due to detection of a fault(e.g., a thermal fault or short circuit). In some embodiments, if it isdetected that the breaker triggered due to a fault, the breaker isprohibited from being remotely closed via remote control. For example,detection of the breaker being triggered due to the bimetal strip or thehigh current solenoid/coil prevents the motor mechanism from beingallowed to run or operate. This satisfies any requirement for a manualreset in the event of the breaker opening due to a short circuit orthermal fault. For example, the remote control of the motor is disableduntil a user manually resets the tripped breaker.

The following are examples of interlocking mechanisms. In someembodiments, an interlock mechanism is used to interlock the motor inthe event that a fault occurs (e.g., thermal fault or short circuit), asdescribed above. In some embodiments, the interlock is a mechanicalinterlock. In other embodiments, the interlock is an electronicinterlock. The interlock may also be an electromechanical interlock.

As one example of a mechanical interlock, the triggers that actuate dueto faults (e.g., bimetal strip or high current solenoid/coil describedabove) are mechanically set up such that if any of those triggers, thisalso causes the movement of a contact that opens the circuit of themotor (e.g., at the terminals), preventing the motor from operating orrunning. The interlock mechanism may then be reset when the user resetsthe breaker mechanism.

As one example of electronic interlocking, in some embodiments, sensorsare placed on the triggers that actuate due to faults (e.g., bimetalstrip or high current solenoid/coil described above). When any of thoseare actuated, this also causes the motor circuit to be opened to preventthe motor from being able to run.

In some embodiments, the breaker does not have a switch. While existingbreakers may have a physical input such as a button or lever for theuser to actuate, the controllable replacement breaker need not have thesame shape or type of existing lever. For example, the controllablebreaker need not have a lever. As one example, the controllable breakermay have an indicator such as a status light (e.g., red and green statusindicator lights), as well as a reset button (where the reset input neednot be a lever even if the existing breaker being replaced included alever). In some embodiments, when the user presses the reset button,this causes the motor mechanism described above to be automatically usedto drive the reset mechanism, resetting the breaker. In otherembodiments, the reset switch physically causes resetting.

As shown in the above example, even though the existing breaker beingreplaced may have had a lever, the intelligent main breaker describedherein need not have the identical or same type of lever. If the smartmain breaker is being implemented in a modular manner (as will bedescribed in further detail below), where there is a standardized corecomponent of a modular controllable breaker, then this standardized corecomponent need not have the identical or same lever. This allows furtherstandardization of the core component so that there need not be corecomponents for different types of levers, switches, reset buttons,lights, indicators, etc.

In some embodiments, the breaker components are designed for robustnessto allow a high cycle life, as the breaker may be opened many times andhave higher cycle time requirements than typical breakers.

Microprocessor Intelligence for Controlling the Controllable Actuator

As described above, the smart main breaker includes a controllableactuator for opening or closing the main breaker to provide gridinterconnect functionality. The inclusion of an additional controllableactuator (e.g., controllable actuators for opening and closing the mainbreaker) allows the safety function of the main breaker to bemaintained, while also providing the ability to control connectionto/disconnection from the grid. In some embodiments, the smart mainbreaker includes a microprocessor 214. In some embodiments, themicrocontroller is a programmable microcontroller on which intelligenceand algorithms can be deployed on (e.g., by programming firmware of theprogrammable microcontroller). Further details regarding suchfunctionality are described below.

In some embodiments, the microprocessor or microcontroller providesonboard intelligence. The onboard intelligence is used to, for example,allow the device to autonomously determine when to turn on or off theconnection to the grid (e.g., by sending instructions or commands to thecontrollable actuators 212 to open or close the main breaker), as wellas other functionality. In some embodiments, by making intelligentdecisions on disconnecting from, or reconnecting to the grid, thisensures seamless power transitions for the homeowner, minimal numbers oftransitions, as well as adherence to any present or future certificationrequirements for smart inverters, grid connected devices, backup powersources, and/or microgrid interconnect devices.

In some embodiments, the microprocessor includes I/O that is connected,for example, to sensors 216, communications 218, etc. The microprocessoralso includes I/O to communicate internally with the controllableactuators 212 for opening and closing the main breaker 202. Thisprovides an interface by which the microprocessor can command thecontrollable actuator to open or close the main breaker to effect griddisconnect or reconnect. The microprocessor also communicates with thecommunications module 218 so that it can receive information from, andsend information to, external devices.

In various embodiments, the smart main breaker is powered by the onsitepower system and/or the grid. In some embodiments, the smart mainbreaker includes a battery. In some embodiments, the battery is includedto operate the switch when both grid power and backup power areunavailable. As shown in this example, the smart main breaker device maybe designed with multiple sources of input power, such as grid side,load side, hardwired, and battery, etc. in order to remain operationalin the maximum number of outage conditions.

Sensors

In this example, the smart main breaker includes sensors 216 for sensingelectrical characteristics such as voltage, current, phase, amplitude,frequency, etc. In some embodiments, the sensors are used to measureboth grid side and load side (e.g., home side) electricalcharacteristics.

Communications

In this example, the device includes communications module 218 forcommunicating with devices external to the device. Examples ofcommunications interfaces include CAN (controller area network)communications, powerline communications (PLC), WiFi, ethernet, or anyother wired and/or wireless communications as appropriate. As oneexample, a communications protocol such as RS485 is used.

As shown above, in some embodiments, the smart main breaker includeselectronics for controlling the triggering (e.g., opening) of thecontacts in the breaker, as well as closing/resetting of the breaker. Insome embodiments, the controllable actuator is implemented using acontrollable solenoid that is connected via wires to the microprocessor.In some embodiments, the microcontroller then puts voltage on the wiresto trigger the actuating mechanisms described above. For example, thecontrollable breaker includes the additional trigger mechanism, motor(e.g., for resetting the breaker after it is opened), an interlockingmechanism as described above, a mechanism for resetting the interlock,as well as other associated electronics.

As described above, in some embodiments, the smart main breaker alsoincludes additional processing logic, communications (e.g., powerlinecommunications, WiFi componentry, etc.), etc. In some embodiments, themechanisms for controlling the opening/closing of the breaker as a relayare designed to not interfere with the safety functioning of the breaker(e.g., so that the breaker can still open in the event of thermal faultsor short circuits).

As also described above, in some embodiments, the smart main breakerincludes a motor reset mechanism. In some embodiments, the smart mainbreaker includes a third or additional controllable trigger mechanism(e.g., solenoid), as described above. As one example, the controllabletrigger mechanism may act, for example, as a type of push button thatbehaves as a manual trip. As one example, the replacement breakerincludes a button that may be toggled or actuated, such as a pushbutton. A controllable solenoid and motor accessory may then be placedover the button. The controllable motor accessory may then actuate thebutton on the smart main breaker. Such an implementation may be used inspace constrained scenarios. For example, suppose that a manual shutoffbutton was included in the replacement breaker, but there is notsufficient space to include a solenoid that could actuate the button. Insome embodiments, the solenoid is placed externally, and is configuredto push that button. Similarly with the motor, if there is insufficientspace within the breaker that goes in the slot, a user input or controlthat a user may toggle or actuate may be included in the breaker thatfits within the slot, where the breaker component is augmented with anexternal motor accessory that actuates the control (e.g., physicalbutton or lever).

Smart Main Breaker Intelligence

As described above, the intelligent main breaker includes amicroprocessor and a controllable actuator for opening and closing themain breaker (e.g., solenoid for opening the main breaker, and a motorfor resetting the main breaker, as described above). In someembodiments, the microprocessor is programmable with a layer offirmware.

In some embodiments, the microprocessor is configured with logic todetermine when to connect to the grid, and when to disconnect from thegrid (e.g., isolate the home from the grid). Based on this intelligence,the microprocessor then issues commands to the controllable actuator toopen/close the main breaker to cause the disconnection from/reconnectionto the grid.

For example, the integrated smart main breaker device is programmed withfunctionality to open due to a brownout or when the grid is down so thatthe solar battery system can isolate from the grid and allow themicrogrid at the home to be stood up.

The decision making on how to control opening and closing of the gridinterconnect switch is based on a variety of inputs including, withoutlimitation:

-   -   Sensor measurements (e.g., from sensors 216): such as        measurements that indicate that the grid is going down    -   Messages: This includes messages communicated from partner        devices. For example, an energy management system for the home        battery system may send a message indicating that it would like        to form a microgrid, and make a request to the integrated        breaker and grid interconnect device to open the grid        interconnect switch.

The following are examples of intelligent functionality supported by theintelligent main breaker described herein.

The use of backup devices such as generators often involve transferswitches, because the generators are not to be operated in parallel withthe grid, and so the transfer switch determines one power source or theother, but does not allow a connection to both simultaneously. This isin contrast to solar battery systems such as that described herein,which operate both on-grid and off-grid. For example, the intelligentmain breaker is configured to enable a power source such as the inverterto be connected in both scenarios. In some embodiments, the intelligentmain breaker and onsite power source (e.g., inverter) are configured tocommunicate with each other. This allows, for example, statusinformation to be passed between the inverter and the integratedbreaker/interconnect. The passing of status information allows theintegrated breaker interconnect device to make appropriate decisions andnot enter an improper state.

As one example, suppose that the inverter (example of an onsite powersource) is not operational (e.g., because somebody has manually openedan inverter relay). Now suppose that a brownout has occurred. In thiscase, because the inverter is down, the integrated device should notopen, and should stay connected to the grid. This is so that the homewill have power as soon as the grid returns. As the inverter is notoperational, it would not be beneficial to disconnect from the grid andisland or isolate the home from the grid (as there would be no powersource to form a microgrid). In some embodiments, the intelligent mainbreaker uses status information of the inverter as an input to determinewhether to open its switch.

As another example, suppose that the inverter was operational, and thatduring a brownout, the smart main breaker device had opened, isolatingthe home from the grid, where the inverter was the sole power source forthe home.

Now suppose that the grid is back up (which the intelligent main breakerdevice determines based on electrical measurements of the grid-sideusing its sensors). The intelligent main breaker should reconnect thehome to the grid in this case. This would also cause the inverter (whichmay be delivering power) to also be connected to the grid. However, thereconnection should not occur until the inverter is synchronized withthe grid (so that the inverter is in grid following mode, where theelectrical characteristics of the inverter's power output follow thegrid). For example, the grid and inverter power source should align inphase, amplitude, and frequency before reconnection to the grid isperformed.

In some embodiments, prior to closing of the main breaker of the smartmain breaker, the microprocessor is configured to determinecharacteristics of the grid for synchronization with the onsite powersource. This includes measuring phase, amplitude, and frequency of thegrid. The smart main breaker then uses its communications module tocommunicate the measured grid electrical characteristics to theinverter. The inverter then uses the grid characteristic information toadjust its output to match the grid side characteristics. In thisexample, the smart main breaker measures the power provided by theinverter on one side, and the characteristics of the power from the gridside and the load side. When the smart main breaker determines that bothsides are synchronized, the microprocessor instructs the controllablemotor to close the main breaker so that the home and the grid arereconnected.

As shown in the examples described herein, the onsite power source canoperate as grid following or grid forming. When the home is on grid, thepower source is to operate in a grid following mode. When the home isoff-grid, the power source is to operate in a grid forming mode (e.g.,where the home is isolated from the grid, and the home is in aneffective island or microgrid state in which the onsite power source isdelivering power to the loads at the site).

As shown in the above examples, in order to determine when it isappropriate for the onsite power source to enter one mode or the other,communication and coordination with the intelligent main breaker isperformed so that status information can be passed between theinterconnect device and the inverter onsite power source. The followingare further embodiments and examples of such coordination.

When the main breaker is open and the onsite power system isdisconnected from the grid, then the onsite power system should be in astate where it is capable of forming a microgrid and providing power tothe loads of the home. As one example, the inverter is programmed toenter grid-forming mode on the condition that the home is disconnectedfrom the grid. Thus, before switching to grid-forming mode, the inverterchecks for the status of the interconnect switch to determine if it isopened or closed. If the smart main breaker/grid interconnect switch isclosed, then the inverter is not permitted to enter grid-forming mode.

As another example, before the inverter switches state to grid-followingmode, the inverter checks with the smart main breaker to determinewhether the grid is back up. If so, then the inverter switches togrid-following mode, and also coordinates resynchronization with thegrid as described above using, for example, information collected andcommunicated by the intelligent main breaker device. As shown in thisexample, in some embodiments, when the main breaker is closed and theonsite power system is connected to the grid, then the onsite powersystem is to operate in a grid following mode, and the onsite powerwaveform and the grid power waveform should be synchronized.

As shown in the above examples, the smart main breaker for solar andbattery systems described herein facilitates communication between thegrid interconnect device and the inverter.

As described above, in some embodiments, the intelligent andcontrollable main breaker device includes a microprocessor so that ithas local autonomy to determine what actions to take. It also includescommunications to allow communication with external intelligent devices(e.g., on site power source), so that information from external devicesmay also be used as input for the microprocessor. In this way,appropriate actions will only be taken when there are correct signalsfrom both devices, such that they are coordinated. However, if there aresome issues with the communication, then the smart main breaker uses itsincluded intelligence so that it can enact secondary or fallback orprimary directive plans to perform safe actions in the event of it beingunable to communicate with the inverter.

As shown in the examples above, in some embodiments, the inverter of theESS is configured to switch between two operating modes: grid-followingmode (when the home is on-grid), and grid-forming mode (when the home isoff-grid). The smart main breaker is configured to determine whether toopen or close the main breaker (effectively disconnecting or connectingthe home from/to the grid). In some embodiments, the state of theinverter (e.g., which operating mode it is in), and the state of thesmart main breaker (e.g., whether the main breaker is opened or closed)are based on coordination between the inverter and the smart mainbreaker. That is, the state of the inverter is based on the state of thesmart main breaker, and vice versa. The behavior of the inverter and thesmart main breaker is also dependent on a variety of factors that arecontext specific.

The following are further embodiments of intelligently determiningwhether to open or close the main breaker of the smart main breakerdescribed herein. In some embodiments, the logic for such adetermination is implemented in firmware and executed by themicroprocessor of the intelligent main breaker.

Embodiments of Disconnecting a Site from the Grid

In some embodiments, the smart main breaker includes logic fordetermining the conditions under which disconnect from the grid ispermitted (and also the conditions under which the smart main breaker isprohibited from disconnecting from the grid.

As one example, suppose that the home is currently connected to thegrid. However, the smart main breaker determines, based on its sensors,that the voltage on the grid is beginning to sag. This is an indicationto the smart main breaker that the grid may be going down. In this case,the smart main breaker prepares to disconnect from the grid.

Prior to opening the main breaker, the smart main breaker is configuredto determine a state of the onsite inverter power source. In thisexample, the smart main breaker first checks to determine whether theinverter is capable of handling the home loads. For example, if theinverter is not capable of handling the home loads, then the smart mainbreaker does not disconnect the home from the grid, as this may causethe inverter to fault or trigger its own relay if it is unable tosupport the loads in the home.

As another example, suppose that the inverter is not available at all(and is non-operational). In this example, it would be a poor userexperience for the customer if the home were disconnected from the grid,as they will then go from a brownout situation to a blackout situation(because the inverter cannot be a power source at all). As such, in someembodiments, the microprocessor of the smart main breaker is programmedsuch that even if it is determined that there is an indication that thegrid is going down (and would be unable to deliver electricity), it doesnot disconnect from the grid if the inverter power source is determinedto be unavailable or incapable of powering the home loads.

As shown in the above examples, prior to taking the action of openingthe main breaker and disconnecting the home from the grid, the smartmain breaker determines whether the onsite power system is in acondition or state to form a microgrid (e.g., is operational, is able toprovide sufficient power for the loads of the home, etc.). If so, thenthe smart main breaker opens the interconnect grid switch, disconnectingthe site from the grid.

The above are examples of coordination between the smart main breakerand a solar battery system that allows the smart main breaker todetermine whether or not to disconnect from the grid.

Embodiments of Reconnecting a Site to the Grid

Coordination between the smart main breaker and the solar battery systemis also performed by the smart main breaker to determine whether or notto close the main breaker and reconnect to the grid. For example, if thegrid comes back after a blackout, it is often the case that the gridwill reach a nominal voltage, and will then sag again, before comingback. If the smart main breaker were to reconnect once the nominalvoltage was reached, and then disconnect once the sagging was detected,and then reconnect once again when the nominal voltage was againreached, it would result in a less than ideal user experience, as thesmart main breaker would be quickly toggling back and forth betweenreconnecting and disconnecting and then reconnecting again to the griddue to the fluctuation in voltage triggering opening/closing of the mainbreaker. In some embodiments, debounce or hysteresis is accounted for.

As another example, suppose that the grid voltage is just at thethreshold of the cutoff of when the smart main breaker would disconnectfrom the grid. That is, the voltage is at a level where it may beappropriate to disconnect from the grid. However, if the voltage ishovering around that level, it would not be ideal for the smart mainbreaker to connect and then disconnect and then reconnect. Instead, thereconnection logic is configured to be hysteretic.

In some embodiments, hysteresis (where the thresholds or conditions foropening/closing the main breaker are different) is implemented by havingdifferent sets of detected grid conditions for connecting to anddisconnecting from the grid. For example, there are different thresholdsor criteria for opening and closing the grid interconnect switch.

In some embodiments, the thresholds are coordinated with the inverter,so that the smart main breaker is aware of the inverter state.

As one example, if the PV array is producing a large amount of power,and the batteries are full, then the dead band (between the thresholdfor opening/closing the main breaker, where the state of the mainbreaker (opened or closed) is not changed while in the dead band) can bebroad or large. As the state of the microgrid is strong and can supportthe home loads stably for a duration of time, there is less urgency toreconnect to the grid, and the threshold level of grid stability beforereconnection can be set higher given this inverter state (e.g., wait forthe grid to be more stable before reconnection).

On the other hand, if the onsite power system will only be able tofurther support the home for a short amount of time, then the dead bandis shrunk, and reconnection to the grid may be performed evenpre-emptively so that the home does not enter a state in which it isboth disconnected form the grid, and the onsite power system is notoperational. For example, if the onsite system is still up, but is closeto becoming non-operational, then the system is pre-emptivelyreconnected to the grid (so that the smart main breaker does not enterinto a situation where it does not have enough power to close the mainbreaker, which could result in the home being unable to be connected tothe grid after the grid has come back).

As shown in the above examples, in some embodiments, to account for suchfluctuation in voltage, the smart main breaker is configured withintelligence to determine the set of conditions by which the home shouldcontinue to be islanded until the smart main breaker is confident thatthe grid is actually back.

The following are additional conditions or criteria for determiningwhether to reconnect to the grid:

-   -   The amount of reserve battery capacity    -   Whether the sun is shining (and solar power is being generated        by the solar panels)    -   The power capacity of the inverter

In some embodiments, loads are supported for as long as they can, andthe smart main breaker waits until the grid voltage is back closer tonominal in order to reconnect.

In some embodiments, resynchronization is performed as part of thereconnection process. For example, suppose that the grid is determinedto be stable and that the onsite power system is also determined to bestable.

In some embodiments, the smart main breaker uses its sensors to measurethe electrical characteristics of the grid. The smart main breaker usesthe grid electrical measurements to determine that the grid is in astable condition.

With respect to onsite power stability, in some embodiments, the smartmain breaker uses its sensors for measuring the onsite power side, andthe microprocessor (which is connected to the sensors via input/output(I/O)) uses the onsite power measurements to determine whether theonsite power system is stable. As another example, the smart mainbreaker receives status information from the ESS indicating itsstability. For example, the smart main breaker queries the onsite powersystem for its stability status. As another example, the ESSperiodically reports or provides such information to the smart mainbreaker.

In order for the onsite power system and the grid to be reconnected,they are required to be synchronized, where the frequency, phase, andamplitude of their voltage must be within a certain tolerance of eachother (that may be defined by a standard). At the point of reconnection,they may not be, and it would be unsafe to reconnect the onsite powersystem and the grid before resynchronization, as it would force onsitepower production to stop. In some embodiments, as part of thereconnection process, before the main breaker of the smart main breakeris closed, the smart main breaker is programmed to transmit a signal ormessage to the inverter or ESS to start changing its power output tomatch the electrical characteristics of the grid. As one example, thesmart main breaker uses its sensors to measure the electricalcharacteristics of the grid, and provides that sensor data to the ESS.The ESS then uses that information to adjust its output waveform andbring it closer to the grid waveform until they are in sync. Once thegrid and ESS waveforms are determined to be in sync, then the action ofclosing the main breaker to reconnect the grid to the onsite powersystem is performed.

In the above examples, the smart main breaker determines to reconnect tothe grid based on detection of the grid returning to a stable condition.The smart main breaker may also be programmed to reconnect the home siteto the grid under other conditions as well.

As one example, suppose that there has been a blackout, and the home hasbeen disconnected from the grid for a period of time. Suppose also thatit has been cloudy, and that there has been minimal solar powerproduced, where the batteries have been drained. In this situation,there is no power for the inverter to deliver.

In this case, based on the onsite power system being unavailable toprovide power (but while there is still sufficient power for the smartmain breaker to operate), the smart main breaker is configured topre-emptively reconnect the home to the grid rather than wait for theinverter to come back. In this way, if the grid comes back online in themiddle of the night (when there is no sun), the house will be powered bythe grid. This is an example of a dark start condition, and in thisexample, the determination of the condition on which to reconnect to thegrid is based on coordination between the inverter and the smart mainbreaker.

In some embodiments, while the smart main breaker is in a disconnectedstate from the grid, the smart main breaker is configured to monitor thehealth or status of the ESS, such as its state of charge (SOC), theamount of power being produced by the panels, etc. That is, the state ofthe microgrid is determined. If the microgrid is determined to be unableto support or power the home loads, then the smart main breakerreconnects the home to the grid.

In some embodiments, the onsite power system also includes variousintelligence. As one example, the onsite power system is configured withthe ability to cause load shedding to reduce the number of loads itneeds to support. This can increase the amount of time in which the homecan be supported by the onsite power system, and make the onsite powersystem more stable.

As another example, in some embodiments, prior to shutting down powergeneration, the onsite power system is configured to transmit a signalto the smart main breaker indicating that it will be going offline.After a timeout period, the smart main breaker will perform reconnectionto the grid.

As described above, the smart main breaker may be powered by either thegrid (e.g., via the busbar), the inverter (e.g., via the busbarconnection, or a hardwired power and communication cable), and/or abattery (e.g., either manufactured directly into the smart main breakeror via a separately packaged battery connected via a dedicated powerconnection). If the grid is down, and the onsite power system is up,then the smart main breaker is powered by the onsite power system (e.g.,by the inverter). In some embodiments, prior to the inverter goingoffline, and while it has sufficient power, the inverter transmits thesignal to the smart main breaker indicating that it will be goingoffline, and also provides enough reserve power so that the smart mainbreaker is able to process the message and then close the interconnectswitch so that the home is reconnected to the grid. In otherembodiments, the smart main breaker includes a battery, and the smartmain breaker reconnects to the grid (by powering the motor to close themain breaker) while it has sufficient power to do so.

Commissioning for Smart Main Breaker

The following are embodiments of commissioning of the smart main breakerdescribed herein. In some embodiments, the commissioning processdescribed herein minimizes installation and commissioning steps, even inthe face of a varied hardware ecosystem.

Smart main breaker commissioning is the process by which a smart mainbreaker is installed into a home. This usually occurs at the same timeas the installation of the ESS. One goal for this process is to proceedautomatically with as little labor as possible.

The smart main breaker microcontroller (e.g., microprocessor describedabove) may be powered in some or all of the following ways:

-   -   1. Powered via a battery that is packaged within the smart main        breaker    -   2. Derive power from the AC voltage applied at the grid side of        the smart main breaker (that is being used as an intelligent,        controllable grid relay)    -   3. Derive power from the AC voltage applied to the load side of        the smart main breaker    -   4. Powered via a hardwire from the ESS (which in some        embodiments is accompanied by a hardwired comms link, such as        CAN or ethernet).

In some embodiments, when a new smart main breaker is installed, it isconfigured to:

-   -   1. Associate with one or more ESS units on site. If        communication is wireless, such as over WiFi, it should ensure        that it is pairing only with an ESS that is connected to the        “Load” side of the relay, and not pair with, for example, an ESS        in an adjoining building. This pairing allows for the relay        state (e.g., state of the main breaker) to be reflected, for        example, in a smartphone app, measure home consumption data, and        other user facing features. This may also include an        authentication step.    -   2. Exchange information with the ESS, which can include a FW        (firmware) version, serial number, etc. for serviceability.    -   3. Boot into an “open” state to ensure that if an ESS is        currently connected to the load side, there is not a large        inrush current when the device boots.    -   4. In some embodiments, the smart main breaker is programmed for        a configurable amperage rating. In some embodiments, unlike a        conventional main breaker, the current rating of the intelligent        main breaker (e.g., the trip current) may be configured, as it        is defined in firmware. If a particular panel requires a 100 A        breaker instead of a 200 A breaker, the same device can be used        and configured to trip at an overcurrent condition equivalent to        a 100 A breaker.

In some embodiments, to associate the smart main breaker to the ESS, thedevice first boots into an “open” mode. If hardwired to the ESS, theassociation is automatic. If wireless, in some embodiments the smartmain breaker connects to a wireless network formed by the ESS. Afterjoining the wireless network, the ESS may then enter a “grid forming”mode whereby it powers the loads in the home (while the smart mainbreaker is still isolating the home from the grid). The smart mainbreaker can then measure the voltage on the load side of the breaker andreport precise measurements of the frequency and voltage to the ESS. Insome embodiments, this measurement is used as a form of authentication.If the ESS and smart main breaker agree on the frequency of the ACvoltage, then it is certain that they are connected to the sameelectrical circuit. If they disagree, then in some embodiments, the ESSremoves the smart main breaker from the wireless network. If they agree,then the ESS and the smart main breaker are considered “paired”. The ESSmay vary the frequency or amplitude of the AC voltage to ensureagreement.

An alternative embodiment of performing the above is to rely on PLC(powerline communications), although PLC may require costly electronics,and may be subject to failure in noisy environments.

In some embodiments, after pairing, the smart main breaker then providesphase offset measurements between the measured AC voltage on the gridside and the AC voltage from the inverter. In some embodiments, thesmart main breaker provides the phase offset via a message back to theESS, and the ESS adjusts the phase until they are back in alignment.

Smart Main Breaker Form Factor

As will be shown in the examples below, embodiments of the smart mainbreaker herein are designed to accommodate existing breaker slots, sothat they can be installed into existing breaker panels, with little tono modification of the existing main panels.

As described above, the smart main breaker is designed or sized to fitwithin an existing panel, and plugs into one or more standard breakerslots of the panel. There is a significant amount of variation inexisting main panels that have been installed in homes, with numerousdifferent kinds of makes and models. In order for a main breaker to beused with a main panel, it is often required to be certified to becompatible with that main panel. Typically, the certification ofbreakers involves panel manufacturers certifying that a given mainbreaker is compatible with their panel, such that the breaker can beincluded or listed on their certification directory. In this case,instead of certification with a utility, before being used in a panel,the smart main breaker device described in would have to be certifiedwith OEMs such as breaker OEMs, panel OEMs, etc.

The intelligent main breaker described herein is designed or sized orconstructed to be certified to be compatible with a large range ofexisting main panels. For example, the design of the physical shape orthe form factor is determined to have the broadest compatibility withexisting panels.

As one example, an evaluation of panel manufacturers and different mainbreaker SKUs for the manufacturers for different amperage sizes isperformed. For the most common form factors, the ones that also sharephysical shapes are also determined in order to arrive at a single formfactor that has the greatest compatibility across panels (e.g., has thehighest compatibility, not just for one panel manufacturer, but acrossmultiple panel manufacturers). For example, all of the form factors formain breakers of different main panel brands, models, and amperage sizesare evaluated. The form factor that is both most common and easiest tomanufacture is determined.

For example, the most common form factor may not be for the most commonpanel. As one example, consider larger amperage sizes of 200 A, which isthe most common main panel amperage size. Despite such a panel being themost common size, each manufacturer has approached the manufacturing ofcompatible 200 A breakers in a variety of different shapes. Instead, themost common form factors across all panels include 100 A and 125 Abreakers that have conventional form factors of being two pole, one inchper pole, with a standard handle tie. That is, the 100 A to 125 Abreaker is the most uniform form factor across panels.

In some embodiments, the form factor of the intelligent main breaker isselected based on this analysis of breaker form factors and the panelsthat they are compatible with. For example, the most common industrystandard form factor across all manufacturers that will fit the mostpanels is selected as one option for the form factor of the smart mainbreaker. For example, breakers from 15 A to 125 A across the four majorbreaker OEMs have form factors that are substantially the same.

The analysis to determine what is the most compatible breaker formfactor can be periodically performed over time, in case form factors forbreakers shift.

As one example, the smart main breaker is implemented around a designutilizing a one inch per pole, two pole breaker, with a form factorsimilar to that of a plug-on stab main breaker. In some embodiments, thesmart main breaker is a multi-piece assembly, with a core trip assembly,with intelligence wrapped around it in a manner that allows the entireassembly to be fit everywhere that the integrated device is certified.

The following is an example of a package or form factor for the smartmain breaker described herein. As described above, in addition toincluding a main breaker for safety functionality, the smart mainbreaker includes various other componentry, such as controllableactuators, sensors, microcontroller, memory, communications, etc.

Existing main breakers are typically quite full. Given the additionalcomponentry of the smart main breaker, the smart main breaker willrequire more space for all of its components than what is typicallyfound in an existing main breaker form factor. In some embodiments, tohouse all of the componentry of a smart main breaker, the smart mainbreaker packaging includes a first portion that has the form factor ofan existing main breaker, and also includes a second “backpack”container portion, where the “backpack” container portion has the shelland sizing of an existing branch breaker. This allows the overallpackage to be plugged into the main breaker slot, as well as theadjacent branch breaker slot/spot.

The following are embodiments of a smart main breaker that, while largerthan a typical existing main breaker, is still able to be fit or placedinto the same location of the existing main breaker being replaced.

For example, the form factor of the smart main breaker allows the smartmain breaker to be installed on the bus bar with other branch breakers.The smart main breaker is constructed such that in addition to occupyingthe same space of a typical main breaker, it also consumes an additionalbreaker slot. For example, the intelligence is packaged into a containerthat is constructed to fit into a free breaker slot. In this example,the smart main breaker has a package that takes up a main breaker slotand an adjacent branch breaker slot.

For example, in some embodiments, for the smart main breaker, theselected breaker form factor is duplicated, where some of the componentsare piggybacked onto the selected breaker form factor in a “backpack”portion.

For example, if a typical hundred-amp breaker is two inches wide, takingup two spaces, then a container is added or attached as part of theoverall smart main breaker package that is also an inch wide, with spacefor the intelligence, communications, etc. This results in a three-inchwide package that takes up three spaces (main breaker slot, which isoften two spaces, along with an adjacent branch breaker slot). In thisexample, the smart main breaker has the form factor of a main breakerwith an additional container (aforementioned “backpack”) for all of theadditional componentry needed to implement the smart main breaker.

FIGS. 3 and 4 illustrate embodiments of locations in an existing panelin which embodiments of the smart main breaker described herein may beinstalled.

FIG. 3 illustrates an example of a location for installation of a smartmain breaker. In this example, the portions of a panel that a smart mainbreaker slots into are shown. For example, suppose that the smart mainbreaker has the form factor of a standard hundred-amp main breaker formfactor, where the form factor is augmented or piggybacked with acontainer that has a form factor of another branch breaker so that itoccupies both the main breaker slot (302), as well as the branch breakerslot (304) adjacent to the main breaker slot. One example of a 100 A or125 A version of a smart main breaker takes up the existing two slots inthe panel for main breakers, with the piggyback container portionoccupying the branch breaker slot adjacent to the main breaker slot.

A typical panel includes a space for a main breaker, as well as spacesfor branch breakers. For example, a standard 125-amp breaker takes uptwo breaker slots/spaces. In some embodiments, the housing of a smartmain breaker is constructed to take up the space of an existing mainbreaker, as well as an adjacent branch breaker space. For example, thepackage of the smart main breaker is sized to occupy the main breakerslot and an adjacent branch breaker slot. The smart main breakerpackaging includes terminals and fasteners to fit into the main breakerslots and adjacent branch breaker slot.

That is, as shown in this example, the smart main breaker is sized totake up the main breaker slot in the panel, as well as consume anadjacent branch breaker slot so that the packaging of the smart mainbreaker includes sufficient space for all of the componentry to allowthe smart main breaker to not only function as a main breaker for safetypurposes, but also as a controllable grid interconnect relay, while alsobeing able to plug into the slots of existing panels.

FIG. 4 illustrates an example of a location for installation of a smartmain breaker. In this example, installation of a 200 A main breaker isdescribed. As one example, the new smart main breaker plugs into theexisting slots 402 allocated for a 200 A main breaker, where additionalspace for intelligence would be included in portions of the smart mainbreaker packaging that fit or slot or plug into adjacent branch breakerslots (e.g., one or both of the adjacent branch breaker spaces 404 and406—the smart main breaker may also be sized so that it occupies othersets of branch breakers adjacent to the main breaker slot). In someembodiments, a 200 A main breaker is implemented by using two 100 Asmart breakers.

The example of FIG. 4 shows a customer's existing panels, as wired. At404 and 406 are examples of branch breakers, such as 20 A branchbreakers. The branch breakers 404 and 406 are in the spaces adjacent tothe main breaker slot 402. In this example, there is a breaker in eachof the adjacent 20 A branch breaker slot. During installation, if thatslot is not available, an electrician can free up the adjacent breakerspace so that the smart main breaker can consume or occupy the existingmain breaker space in the panel, as well as the adjacent branch breakerspace that is next to the main breaker slot.

As one example, a larger 150 A or 200 A version of the smart mainbreaker includes a portion that takes up four breaker spaces, with atwo-space piggyback or “backpack”. In some embodiments, the smart mainbreaker is implemented as a one-piece design that includes all of thecomponentry, and that plugs into the breaker panel (e.g., into the mainbreaker slots and adjacent branch breaker slots) as a single unit.

In some embodiments, the smart main breaker is implemented as a plug onbreaker. The smart main breaker is installed onto the bus bar stabs ofthe main panel. When installing, the installer wires the gridconnection, as well as the communication connection to the intelligentonsite power source.

As described herein, having a smart main breaker that is sized toutilize adjacent breaker slots provides the ability to take an existingform factor and grow it in a dimension that allows the smart mainbreaker to incorporate the componentry for implementing smart gridinterconnect relay functionality, while still being able to be installedin an existing electrical panel.

Modular Intelligent Main Breaker

As one example, the controllable breaker is modular and may beconstructed as multiple pieces. One piece for example is a standardizedcore component. Other pieces include adapters (e.g., cases) attached tothe core component to create breakers of varying sizes and shapes toaccommodate different types of breaker slots. This allows variable sizedcontrollable main breakers to be created for various types of situations(where breakers may be of various shapes and sizes, with differentamperage ratings).

The following is an example of a controllable main breaker that includesa core component. Existing breakers in the United States typically havetwo input terminals and two output terminals (to break line 1 and line 2in a 240V system).

The modular controllable breaker design described herein may be used oradapted to create a controllable breaker that matches various aspects ofthe existing breaker that is being replaced, such as matching mountingfeatures (e.g., how the breaker mounts into the breaker panel), shapes,terminal locations, etc.

As one example, consider a 200 A controllable main breaker. Thecontrollable main breaker includes a core component, where the corecomponent includes the common functionality used to function as a mainbreaker as well as to be controllable. For example, the core componentincludes the componentry of the architecture described in conjunctionwith FIG. 2 . The core component may be of a size that fits within theenvelope of existing 200 A controllable breakers to be replaced. Forexample, existing breakers may be overlaid to determine the intersectionof common space. This may be used to determine the dimensions of thecore component/package (other core component dimensions may bedetermined by performing similar analysis of existing breakers to bereplaced or breaker slots to be filled). In some embodiments, the corecomponent or unit includes terminals, which will be used to attach toadapters to generate particular instances or variations of controllablebreakers.

For example, to produce an individual version of a controllable mainbreaker (e.g., to replace a specific existing main breaker), the corecomponent is augmented with an additional piece (e.g., plasticcomponent), where the additional piece makes up the difference betweenwhat the overall main breaker form factor should be and what the coreis. In some embodiments, the added piece includes terminals that makecontact with the input/output terminals of the core component. Thisresults in a modular controllable main breaker design.

In some embodiments, a specific variation of a controllable main breakeris generated by coupling an adapter to the core component. As oneexample, an adaptor piece may be snapped on to a core component, wherethere are different adapters for different types of desired main breakerforms. As another example, a specific instance of a controllable breakeris generated by adding to molding. For example, different molds may becreated around the core component.

The modular nature of the controllable main breaker described aboveprovides manufacturing benefits. For example, different cases may becreated with different terminals embedded in them that electricallyconnect to the terminals of the core component. The core component maysnap into the case, transforming it into a desired main breaker formfactor/implementation. In this example, there is a standardized corethat may be transformed into various different types of breakers viaadaptors, additional molding, etc. In some embodiments, the cases aredesigned to match various aspects or features of the existing breakersto be replaced. For example, the case may be designed to fill the slotor receptacle that is normally filled by an existing breaker.

Using such a modular controllable main breaker design, a controllablemain breaker instance may be created to replace an existing main breakerby simply swapping out the existing main breaker with the new one thathas been created to be of the same form. In this way, a controllablemain breaker (that can also be used as a grid interconnect relay) can beinstalled without requiring installation of a new panel (which wouldinvolve moving loads over, inserting relays, etc.).

The use of a standardized or common core component provides simplicityin certification as well. For example, one aspect of UL certification isfailure mode analysis. In this example, as multiple variants ofcontrollable main breakers may be created starting from a base corecomponent, only the standardized core component (which includes thefunctional components in various embodiments) need be tested oranalyzed. Similar efficiencies in thermal testing may also be realizedusing such a modular controllable main breaker design. In this example,the standardized core component is a single package that includes thesame set of electronics or components that is common across the variousbreaker variations. This allows more efficient and faster(re)certification of controllable main breakers. As shown in theseexamples, there is a common core component that encompasses commonfunctionality and hardware that may be included in every designvariation.

In some embodiments, the electronics for controlling the triggering(e.g., opening) of the contacts in the breaker, as well asclosing/resetting of the main breaker may be external to the corecomponent/breaker component. For example, wires from the controllablesolenoid may come out of the main breaker/core component, which connectto an external controller. The controller may then put voltage on thewires to trigger the actuating mechanisms described above. Suchelectronics may be placed in the external unit in the event that thereis not sufficient space within the portion of the main breaker that goesinto a main breaker slot. For example, in some embodiments, thecontrollable main breaker includes the additional trigger mechanism,motor (e.g., for resetting the breaker after it is opened), aninterlocking mechanism as described above, a mechanism for resetting theinterlock, as well as other associated electronics. The external unitmay then include, for example, additional processing logic,communications (e.g., powerline communications, WiFi componentry, etc.),etc., with a set of wires that go between the controllable main breakercomponent and the external unit. In some embodiments, the mechanisms forcontrolling the opening/closing of the main breaker as a gridinterconnect relay are designed to not interfere with the safetyfunctioning of the main breaker (e.g., so that the main breaker canstill open in the event of thermal faults or short circuits).

In some embodiments, the motor for resetting the main breaker on demandis also external to the main breaker core component. As one example,after a replacement main breaker is wired into the breaker panel, andbefore the door of the main breaker panel is closed, a unit is installedon top of the main breaker or portion of the main breaker in the mainbreaker slot, where this unit includes the motor reset mechanism. Insome embodiments, the third or additional controllable trigger mechanism(e.g., solenoid) may also be external to the main body or core of themain breaker. The controllable trigger mechanism may act, for example,as a type of push button that behaves as a manual trip. As one example,the replacement breaker core may include a button that may be toggled oractuated, such as a push button. A controllable solenoid and motoraccessory may then be placed on the outside of the main breakercomponent, over the button. The controllable external motor accessorymay then actuate the button on the breaker core component. Such animplementation may be used in space constrained scenarios. For example,suppose that a manual shutoff button was included in the replacementbreaker, but there is not sufficient space to include a solenoid thatcould actuate the button. In some embodiments, the solenoid is placed inan external unit, where the solenoid is configured to push that button.Similarly with the motor, if there is insufficient space within the mainbreaker that goes in the slot (or slots), a user input or control that auser may toggle or actuate may be included in the main breaker componentthat fits within the slot, where the main breaker component is augmentedwith an external motor accessory that actuates the control (e.g.,physical button or lever).

Retrofit Robotic Accessory

The following are additional embodiments of a controllable main breakerthat also functions as a grid interface relay. Existing main breakersare designed to be difficult to sabotage or be defeated by a user. Forexample, even if a user attempts to hold a lever closed (to keep thecircuit closed), if a fault occurs (e.g., due to a thermal fault or highcurrent due to a short circuit event), the main breaker will still openthe circuit. That is, regardless of how the user is manipulating anexternal reset lever or button, the main breaker will trigger in theevent of a fault for safety purposes. Further, with existing mainbreakers, in some cases, after tripping, the lever for the breaker goesto a middle position. If the user pushes on the lever towards the onposition, they are not able to turn the breaker on. Rather, the usermust first switch the breaker to off and then pull it back on. Even if aperson is holding the main breaker lever in the on position, internally,the main breaker will still be able to trigger due to a fault. That is,a person cannot force the main breaker to stay on by jamming the leverto one side. Within the main breaker, the main breaker mechanism willopen the contacts regardless of the position of the lever.

In some embodiments, the controllable main breaker is implemented byimplementing an actuator accessory or unit such as a robotic actuatordevice that goes over or otherwise augments or manipulates an existingmain breaker, where the robotic device is configured, for example, toactuate the existing lever or button of the existing breaker. In thisexample, the existing breaker is able to maintain safety using theabove-mentioned safety mechanisms even if the robotic device is notworking properly. For example, even if the robotic device weremalfunctioning and attempted to hold the breaker open, the roboticdevice would not be able to prevent the main breaker from opening due toa fault, as the main breaker will be able to open if needed, even if therobotic device is holding the lever in the on direction.

In some embodiments, the robotic device includes a spring-loadedmechanism that is able to snap the lever or push-button mechanism of themain breaker to the off position very quickly (opening the interface tothe meter, thereby disconnecting the home from the grid). Turning backon of the main breaker (and allowing current to flow again) need not beas aggressive (e.g., a slower, more motorized action may be used to pusha lever on). Here, the robotic device can both turn on and off anexisting breaker.

By using such a robotic device, controllability may be added to any mainbreaker, without having to uninstall that existing main breaker. In someembodiments, any additional hardware for introducing controllability isincluded in the external robotic device, which is placed over anexisting main circuit breaker. In some embodiments, the robotic deviceis low profile so that after installation, the door of the circuitbreaker panel can still be closed. As shown in these examples,controllability of the main breaker (to make it into a controllable gridinterconnect relay) is added without having to design a new type of mainbreaker, and UL certification would not need to be performed (or mayotherwise be simplified).

In some embodiments, the robotic device receives power by connecting therobotic device to wires that run out of the panel (e.g., through aconduit), allowing the robotic device to tap into whatever voltage itneeds. In other embodiments, the breaker includes tunnels in the plasticof the breaker, such that wires can be run through the surface of thebreaker and end up inside of the box.

In other embodiments, rather than having wires that pass through theplastic of the breaker, a replacement breaker may be introduced thatincludes a plug or receptacle on its face. The robotic device may thenplug directly into the connector or terminal or receptacle presented onthe front surface of the main breaker. In this way, when plugged in,anything needed by the robotic device may be passed from inside the box,such as line 1 and line 2 voltage. In some embodiments, the main breakerwith the receptacle, as well as the robotic actuator, are madetouch-safe.

Although the foregoing embodiments have been described in some detailfor purposes of clarity of understanding, the invention is not limitedto the details provided. There are many alternative ways of implementingthe invention. The disclosed embodiments are illustrative and notrestrictive.

What is claimed is:
 1. A controllable main breaker, comprising: a mainbreaker sized to fit within an existing panel slot of an electricalpanel, wherein the main breaker comprises a trigger to open the mainbreaker in response to a thermal fault or an overcurrent condition; anauxiliary shell sized to fit within at least one adjacent breaker slot;wherein the auxiliary shell includes a controllable actuator thatmechanically opens the main breaker; and a microcontroller, wherein thecontrollable actuator is controlled at least in part by themicrocontroller; wherein prior to commanding closing of the mainbreaker, the microcontroller is configured to facilitate synchronizationbetween an onsite power source and a grid.
 2. The controllable mainbreaker of claim 1, wherein the controllable actuator comprises asolenoid that, when triggered, mechanically opens the main breaker. 3.The controllable main breaker of claim 1, further comprising a motorconfigured to close the main breaker.
 4. The controllable main breakerof claim 3, further comprising an electrical, mechanical, orelectromechanical interlock that is configured to prevent the motor fromclosing the main breaker in the event that the main breaker isdetermined to have been opened due to one of the thermal fault or theovercurrent condition.
 5. The controllable main breaker of claim 1,wherein prior to commanding opening of the main breaker, themicrocontroller is configured to determine that the onsite power sourceis capable of forming a microgrid.
 6. The controllable main breaker ofclaim 1, further comprising a set of sensors, wherein the set of sensorsis configured to measure electrical characteristics of the grid, andwherein the microcontroller facilitates synchronization between theonsite power source and the grid at least in part by providing measuredelectrical characteristics of the grid to the onsite power source. 7.The controllable main breaker of claim 6, wherein the microcontrollercommands closing of the main breaker based at least in part on adetermination that the onsite power source is synchronized to the grid.8. The controllable main breaker of claim 1, further comprising acommunications interface, wherein the controllable main breaker isconfigured to communicate with the onsite power source via thecommunications interface.